646 lines
18 KiB
C
646 lines
18 KiB
C
/* Stabs in sections linking support.
|
||
Copyright 1996, 1997 Free Software Foundation, Inc.
|
||
Written by Ian Lance Taylor, Cygnus Support.
|
||
|
||
This file is part of BFD, the Binary File Descriptor library.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 2 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program; if not, write to the Free Software
|
||
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
||
|
||
/* This file contains support for linking stabs in sections, as used
|
||
on COFF and ELF. */
|
||
|
||
#include "bfd.h"
|
||
#include "sysdep.h"
|
||
#include "libbfd.h"
|
||
#include "aout/stab_gnu.h"
|
||
|
||
#include <ctype.h>
|
||
|
||
/* Stabs entries use a 12 byte format:
|
||
4 byte string table index
|
||
1 byte stab type
|
||
1 byte stab other field
|
||
2 byte stab desc field
|
||
4 byte stab value
|
||
FIXME: This will have to change for a 64 bit object format.
|
||
|
||
The stabs symbols are divided into compilation units. For the
|
||
first entry in each unit, the type of 0, the value is the length of
|
||
the string table for this unit, and the desc field is the number of
|
||
stabs symbols for this unit. */
|
||
|
||
#define STRDXOFF (0)
|
||
#define TYPEOFF (4)
|
||
#define OTHEROFF (5)
|
||
#define DESCOFF (6)
|
||
#define VALOFF (8)
|
||
#define STABSIZE (12)
|
||
|
||
/* A hash table used for header files with N_BINCL entries. */
|
||
|
||
struct stab_link_includes_table
|
||
{
|
||
struct bfd_hash_table root;
|
||
};
|
||
|
||
/* A linked list of totals that we have found for a particular header
|
||
file. */
|
||
|
||
struct stab_link_includes_totals
|
||
{
|
||
struct stab_link_includes_totals *next;
|
||
bfd_vma total;
|
||
};
|
||
|
||
/* An entry in the header file hash table. */
|
||
|
||
struct stab_link_includes_entry
|
||
{
|
||
struct bfd_hash_entry root;
|
||
/* List of totals we have found for this file. */
|
||
struct stab_link_includes_totals *totals;
|
||
};
|
||
|
||
/* Look up an entry in an the header file hash table. */
|
||
|
||
#define stab_link_includes_lookup(table, string, create, copy) \
|
||
((struct stab_link_includes_entry *) \
|
||
bfd_hash_lookup (&(table)->root, (string), (create), (copy)))
|
||
|
||
/* This structure is used to hold a list of N_BINCL symbols, some of
|
||
which might be converted into N_EXCL symbols. */
|
||
|
||
struct stab_excl_list
|
||
{
|
||
/* The next symbol to convert. */
|
||
struct stab_excl_list *next;
|
||
/* The offset to this symbol in the section contents. */
|
||
bfd_size_type offset;
|
||
/* The value to use for the symbol. */
|
||
bfd_vma val;
|
||
/* The type of this symbol (N_BINCL or N_EXCL). */
|
||
int type;
|
||
};
|
||
|
||
/* This structure is stored with each .stab section. */
|
||
|
||
struct stab_section_info
|
||
{
|
||
/* This is a linked list of N_BINCL symbols which should be
|
||
converted into N_EXCL symbols. */
|
||
struct stab_excl_list *excls;
|
||
|
||
/* This is used to map input stab offsets within their sections
|
||
to output stab offsets, to take into account stabs that have
|
||
been deleted. If it is NULL, the output offsets are the same
|
||
as the input offsets, because no stabs have been deleted from
|
||
this section. Otherwise the i'th entry is the number of
|
||
bytes of stabs that have been deleted prior to the i'th
|
||
stab. */
|
||
bfd_size_type *cumulative_skips;
|
||
|
||
/* This is an array of string indices. For each stab symbol, we
|
||
store the string index here. If a stab symbol should not be
|
||
included in the final output, the string index is -1. */
|
||
bfd_size_type stridxs[1];
|
||
};
|
||
|
||
/* This structure is used to keep track of stabs in sections
|
||
information while linking. */
|
||
|
||
struct stab_info
|
||
{
|
||
/* A hash table used to hold stabs strings. */
|
||
struct bfd_strtab_hash *strings;
|
||
/* The header file hash table. */
|
||
struct stab_link_includes_table includes;
|
||
/* The first .stabstr section. */
|
||
asection *stabstr;
|
||
};
|
||
|
||
static struct bfd_hash_entry *stab_link_includes_newfunc
|
||
PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
|
||
|
||
/* The function to create a new entry in the header file hash table. */
|
||
|
||
static struct bfd_hash_entry *
|
||
stab_link_includes_newfunc (entry, table, string)
|
||
struct bfd_hash_entry *entry;
|
||
struct bfd_hash_table *table;
|
||
const char *string;
|
||
{
|
||
struct stab_link_includes_entry *ret =
|
||
(struct stab_link_includes_entry *) entry;
|
||
|
||
/* Allocate the structure if it has not already been allocated by a
|
||
subclass. */
|
||
if (ret == (struct stab_link_includes_entry *) NULL)
|
||
ret = ((struct stab_link_includes_entry *)
|
||
bfd_hash_allocate (table,
|
||
sizeof (struct stab_link_includes_entry)));
|
||
if (ret == (struct stab_link_includes_entry *) NULL)
|
||
return (struct bfd_hash_entry *) ret;
|
||
|
||
/* Call the allocation method of the superclass. */
|
||
ret = ((struct stab_link_includes_entry *)
|
||
bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
|
||
if (ret)
|
||
{
|
||
/* Set local fields. */
|
||
ret->totals = NULL;
|
||
}
|
||
|
||
return (struct bfd_hash_entry *) ret;
|
||
}
|
||
|
||
/* This function is called for each input file from the add_symbols
|
||
pass of the linker. */
|
||
|
||
boolean
|
||
_bfd_link_section_stabs (abfd, psinfo, stabsec, stabstrsec, psecinfo)
|
||
bfd *abfd;
|
||
PTR *psinfo;
|
||
asection *stabsec;
|
||
asection *stabstrsec;
|
||
PTR *psecinfo;
|
||
{
|
||
boolean first;
|
||
struct stab_info *sinfo;
|
||
bfd_size_type count;
|
||
struct stab_section_info *secinfo;
|
||
bfd_byte *stabbuf = NULL;
|
||
bfd_byte *stabstrbuf = NULL;
|
||
bfd_byte *sym, *symend;
|
||
bfd_size_type stroff, next_stroff, skip;
|
||
bfd_size_type *pstridx;
|
||
|
||
if (stabsec->_raw_size == 0
|
||
|| stabstrsec->_raw_size == 0)
|
||
{
|
||
/* This file does not contain stabs debugging information. */
|
||
return true;
|
||
}
|
||
|
||
if (stabsec->_raw_size % STABSIZE != 0)
|
||
{
|
||
/* Something is wrong with the format of these stab symbols.
|
||
Don't try to optimize them. */
|
||
return true;
|
||
}
|
||
|
||
if ((stabstrsec->flags & SEC_RELOC) != 0)
|
||
{
|
||
/* We shouldn't see relocations in the strings, and we aren't
|
||
prepared to handle them. */
|
||
return true;
|
||
}
|
||
|
||
if ((stabsec->output_section != NULL
|
||
&& bfd_is_abs_section (stabsec->output_section))
|
||
|| (stabstrsec->output_section != NULL
|
||
&& bfd_is_abs_section (stabstrsec->output_section)))
|
||
{
|
||
/* At least one of the sections is being discarded from the
|
||
link, so we should just ignore them. */
|
||
return true;
|
||
}
|
||
|
||
first = false;
|
||
|
||
if (*psinfo == NULL)
|
||
{
|
||
/* Initialize the stabs information we need to keep track of. */
|
||
first = true;
|
||
*psinfo = (PTR) bfd_alloc (abfd, sizeof (struct stab_info));
|
||
if (*psinfo == NULL)
|
||
goto error_return;
|
||
sinfo = (struct stab_info *) *psinfo;
|
||
sinfo->strings = _bfd_stringtab_init ();
|
||
if (sinfo->strings == NULL)
|
||
goto error_return;
|
||
if (! bfd_hash_table_init_n (&sinfo->includes.root,
|
||
stab_link_includes_newfunc,
|
||
251))
|
||
goto error_return;
|
||
sinfo->stabstr = bfd_make_section_anyway (abfd, ".stabstr");
|
||
sinfo->stabstr->flags |= SEC_HAS_CONTENTS | SEC_READONLY | SEC_DEBUGGING;
|
||
}
|
||
|
||
sinfo = (struct stab_info *) *psinfo;
|
||
|
||
/* Initialize the information we are going to store for this .stab
|
||
section. */
|
||
|
||
count = stabsec->_raw_size / STABSIZE;
|
||
|
||
*psecinfo = bfd_alloc (abfd,
|
||
(sizeof (struct stab_section_info)
|
||
+ (count - 1) * sizeof (bfd_size_type)));
|
||
if (*psecinfo == NULL)
|
||
goto error_return;
|
||
|
||
secinfo = (struct stab_section_info *) *psecinfo;
|
||
secinfo->excls = NULL;
|
||
secinfo->cumulative_skips = NULL;
|
||
memset (secinfo->stridxs, 0, count * sizeof (bfd_size_type));
|
||
|
||
/* Read the stabs information from abfd. */
|
||
|
||
stabbuf = (bfd_byte *) bfd_malloc (stabsec->_raw_size);
|
||
stabstrbuf = (bfd_byte *) bfd_malloc (stabstrsec->_raw_size);
|
||
if (stabbuf == NULL || stabstrbuf == NULL)
|
||
goto error_return;
|
||
|
||
if (! bfd_get_section_contents (abfd, stabsec, stabbuf, 0,
|
||
stabsec->_raw_size)
|
||
|| ! bfd_get_section_contents (abfd, stabstrsec, stabstrbuf, 0,
|
||
stabstrsec->_raw_size))
|
||
goto error_return;
|
||
|
||
/* Look through the stabs symbols, work out the new string indices,
|
||
and identify N_BINCL symbols which can be eliminated. */
|
||
|
||
stroff = 0;
|
||
next_stroff = 0;
|
||
skip = 0;
|
||
|
||
symend = stabbuf + stabsec->_raw_size;
|
||
for (sym = stabbuf, pstridx = secinfo->stridxs;
|
||
sym < symend;
|
||
sym += STABSIZE, ++pstridx)
|
||
{
|
||
int type;
|
||
const char *string;
|
||
|
||
if (*pstridx != 0)
|
||
{
|
||
/* This symbol has already been handled by an N_BINCL pass. */
|
||
continue;
|
||
}
|
||
|
||
type = sym[TYPEOFF];
|
||
|
||
if (type == 0)
|
||
{
|
||
/* Special type 0 stabs indicate the offset to the next
|
||
string table. We only copy the very first one. */
|
||
stroff = next_stroff;
|
||
next_stroff += bfd_get_32 (abfd, sym + 8);
|
||
if (! first)
|
||
{
|
||
*pstridx = (bfd_size_type) -1;
|
||
++skip;
|
||
continue;
|
||
}
|
||
first = false;
|
||
}
|
||
|
||
/* Store the string in the hash table, and record the index. */
|
||
string = ((char *) stabstrbuf
|
||
+ stroff
|
||
+ bfd_get_32 (abfd, sym + STRDXOFF));
|
||
*pstridx = _bfd_stringtab_add (sinfo->strings, string, true, true);
|
||
|
||
/* An N_BINCL symbol indicates the start of the stabs entries
|
||
for a header file. We need to scan ahead to the next N_EINCL
|
||
symbol, ignoring nesting, adding up all the characters in the
|
||
symbol names, not including the file numbers in types (the
|
||
first number after an open parenthesis). */
|
||
if (type == N_BINCL)
|
||
{
|
||
bfd_vma val;
|
||
int nest;
|
||
bfd_byte *incl_sym;
|
||
struct stab_link_includes_entry *incl_entry;
|
||
struct stab_link_includes_totals *t;
|
||
struct stab_excl_list *ne;
|
||
|
||
val = 0;
|
||
nest = 0;
|
||
for (incl_sym = sym + STABSIZE;
|
||
incl_sym < symend;
|
||
incl_sym += STABSIZE)
|
||
{
|
||
int incl_type;
|
||
|
||
incl_type = incl_sym[TYPEOFF];
|
||
if (incl_type == 0)
|
||
break;
|
||
else if (incl_type == N_EINCL)
|
||
{
|
||
if (nest == 0)
|
||
break;
|
||
--nest;
|
||
}
|
||
else if (incl_type == N_BINCL)
|
||
++nest;
|
||
else if (nest == 0)
|
||
{
|
||
const char *str;
|
||
|
||
str = ((char *) stabstrbuf
|
||
+ stroff
|
||
+ bfd_get_32 (abfd, incl_sym + STRDXOFF));
|
||
for (; *str != '\0'; str++)
|
||
{
|
||
val += *str;
|
||
if (*str == '(')
|
||
{
|
||
/* Skip the file number. */
|
||
++str;
|
||
while (isdigit ((unsigned char) *str))
|
||
++str;
|
||
--str;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If we have already included a header file with the same
|
||
value, then replaced this one with an N_EXCL symbol. */
|
||
incl_entry = stab_link_includes_lookup (&sinfo->includes, string,
|
||
true, true);
|
||
if (incl_entry == NULL)
|
||
goto error_return;
|
||
|
||
for (t = incl_entry->totals; t != NULL; t = t->next)
|
||
if (t->total == val)
|
||
break;
|
||
|
||
/* Record this symbol, so that we can set the value
|
||
correctly. */
|
||
ne = (struct stab_excl_list *) bfd_alloc (abfd, sizeof *ne);
|
||
if (ne == NULL)
|
||
goto error_return;
|
||
ne->offset = sym - stabbuf;
|
||
ne->val = val;
|
||
ne->type = N_BINCL;
|
||
ne->next = secinfo->excls;
|
||
secinfo->excls = ne;
|
||
|
||
if (t == NULL)
|
||
{
|
||
/* This is the first time we have seen this header file
|
||
with this set of stabs strings. */
|
||
t = ((struct stab_link_includes_totals *)
|
||
bfd_hash_allocate (&sinfo->includes.root, sizeof *t));
|
||
if (t == NULL)
|
||
goto error_return;
|
||
t->total = val;
|
||
t->next = incl_entry->totals;
|
||
incl_entry->totals = t;
|
||
}
|
||
else
|
||
{
|
||
bfd_size_type *incl_pstridx;
|
||
|
||
/* We have seen this header file before. Tell the final
|
||
pass to change the type to N_EXCL. */
|
||
ne->type = N_EXCL;
|
||
|
||
/* Mark the skipped symbols. */
|
||
|
||
nest = 0;
|
||
for (incl_sym = sym + STABSIZE, incl_pstridx = pstridx + 1;
|
||
incl_sym < symend;
|
||
incl_sym += STABSIZE, ++incl_pstridx)
|
||
{
|
||
int incl_type;
|
||
|
||
incl_type = incl_sym[TYPEOFF];
|
||
|
||
if (incl_type == N_EINCL)
|
||
{
|
||
if (nest == 0)
|
||
{
|
||
*incl_pstridx = (bfd_size_type) -1;
|
||
++skip;
|
||
break;
|
||
}
|
||
--nest;
|
||
}
|
||
else if (incl_type == N_BINCL)
|
||
++nest;
|
||
else if (nest == 0)
|
||
{
|
||
*incl_pstridx = (bfd_size_type) -1;
|
||
++skip;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
free (stabbuf);
|
||
stabbuf = NULL;
|
||
free (stabstrbuf);
|
||
stabstrbuf = NULL;
|
||
|
||
/* We need to set the section sizes such that the linker will
|
||
compute the output section sizes correctly. We set the .stab
|
||
size to not include the entries we don't want. We set
|
||
SEC_EXCLUDE for the .stabstr section, so that it will be dropped
|
||
from the link. We record the size of the strtab in the first
|
||
.stabstr section we saw, and make sure we don't set SEC_EXCLUDE
|
||
for that section. */
|
||
stabsec->_cooked_size = (count - skip) * STABSIZE;
|
||
if (stabsec->_cooked_size == 0)
|
||
stabsec->flags |= SEC_EXCLUDE;
|
||
stabstrsec->flags |= SEC_EXCLUDE;
|
||
sinfo->stabstr->_cooked_size = _bfd_stringtab_size (sinfo->strings);
|
||
|
||
/* Calculate the `cumulative_skips' array now that stabs have been
|
||
deleted for this section. */
|
||
|
||
if (skip != 0)
|
||
{
|
||
bfd_size_type i, offset;
|
||
bfd_size_type *pskips;
|
||
|
||
secinfo->cumulative_skips =
|
||
(bfd_size_type *) bfd_alloc (abfd, count * sizeof (bfd_size_type));
|
||
if (secinfo->cumulative_skips == NULL)
|
||
goto error_return;
|
||
|
||
pskips = secinfo->cumulative_skips;
|
||
pstridx = secinfo->stridxs;
|
||
offset = 0;
|
||
|
||
for (i = 0; i < count; i++, pskips++, pstridx++)
|
||
{
|
||
*pskips = offset;
|
||
if (*pstridx == (bfd_size_type) -1)
|
||
offset += STABSIZE;
|
||
}
|
||
|
||
BFD_ASSERT (offset != 0);
|
||
}
|
||
|
||
return true;
|
||
|
||
error_return:
|
||
if (stabbuf != NULL)
|
||
free (stabbuf);
|
||
if (stabstrbuf != NULL)
|
||
free (stabstrbuf);
|
||
return false;
|
||
}
|
||
|
||
/* Write out the stab section. This is called with the relocated
|
||
contents. */
|
||
|
||
boolean
|
||
_bfd_write_section_stabs (output_bfd, psinfo, stabsec, psecinfo, contents)
|
||
bfd *output_bfd;
|
||
PTR *psinfo;
|
||
asection *stabsec;
|
||
PTR *psecinfo;
|
||
bfd_byte *contents;
|
||
{
|
||
struct stab_info *sinfo;
|
||
struct stab_section_info *secinfo;
|
||
struct stab_excl_list *e;
|
||
bfd_byte *sym, *tosym, *symend;
|
||
bfd_size_type *pstridx;
|
||
|
||
sinfo = (struct stab_info *) *psinfo;
|
||
secinfo = (struct stab_section_info *) *psecinfo;
|
||
|
||
if (secinfo == NULL)
|
||
return bfd_set_section_contents (output_bfd, stabsec->output_section,
|
||
contents, stabsec->output_offset,
|
||
stabsec->_raw_size);
|
||
|
||
/* Handle each N_BINCL entry. */
|
||
for (e = secinfo->excls; e != NULL; e = e->next)
|
||
{
|
||
bfd_byte *excl_sym;
|
||
|
||
BFD_ASSERT (e->offset < stabsec->_raw_size);
|
||
excl_sym = contents + e->offset;
|
||
bfd_put_32 (output_bfd, e->val, excl_sym + VALOFF);
|
||
excl_sym[TYPEOFF] = e->type;
|
||
}
|
||
|
||
/* Copy over all the stabs symbols, omitting the ones we don't want,
|
||
and correcting the string indices for those we do want. */
|
||
tosym = contents;
|
||
symend = contents + stabsec->_raw_size;
|
||
for (sym = contents, pstridx = secinfo->stridxs;
|
||
sym < symend;
|
||
sym += STABSIZE, ++pstridx)
|
||
{
|
||
if (*pstridx != (bfd_size_type) -1)
|
||
{
|
||
if (tosym != sym)
|
||
memcpy (tosym, sym, STABSIZE);
|
||
bfd_put_32 (output_bfd, *pstridx, tosym + STRDXOFF);
|
||
|
||
if (sym[TYPEOFF] == 0)
|
||
{
|
||
/* This is the header symbol for the stabs section. We
|
||
don't really need one, since we have merged all the
|
||
input stabs sections into one, but we generate one
|
||
for the benefit of readers which expect to see one. */
|
||
BFD_ASSERT (sym == contents);
|
||
bfd_put_32 (output_bfd, _bfd_stringtab_size (sinfo->strings),
|
||
tosym + VALOFF);
|
||
bfd_put_16 (output_bfd,
|
||
stabsec->output_section->_raw_size / STABSIZE - 1,
|
||
tosym + DESCOFF);
|
||
}
|
||
|
||
tosym += STABSIZE;
|
||
}
|
||
}
|
||
|
||
BFD_ASSERT (tosym - contents == stabsec->_cooked_size);
|
||
|
||
return bfd_set_section_contents (output_bfd, stabsec->output_section,
|
||
contents, stabsec->output_offset,
|
||
stabsec->_cooked_size);
|
||
}
|
||
|
||
/* Write out the .stabstr section. */
|
||
|
||
boolean
|
||
_bfd_write_stab_strings (output_bfd, psinfo)
|
||
bfd *output_bfd;
|
||
PTR *psinfo;
|
||
{
|
||
struct stab_info *sinfo;
|
||
|
||
sinfo = (struct stab_info *) *psinfo;
|
||
|
||
if (sinfo == NULL)
|
||
return true;
|
||
|
||
BFD_ASSERT ((sinfo->stabstr->output_offset
|
||
+ _bfd_stringtab_size (sinfo->strings))
|
||
<= sinfo->stabstr->output_section->_raw_size);
|
||
|
||
if (bfd_seek (output_bfd,
|
||
(sinfo->stabstr->output_section->filepos
|
||
+ sinfo->stabstr->output_offset),
|
||
SEEK_SET) != 0)
|
||
return false;
|
||
|
||
if (! _bfd_stringtab_emit (output_bfd, sinfo->strings))
|
||
return false;
|
||
|
||
/* We no longer need the stabs information. */
|
||
_bfd_stringtab_free (sinfo->strings);
|
||
bfd_hash_table_free (&sinfo->includes.root);
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Adjust an address in the .stab section. Given OFFSET within
|
||
STABSEC, this returns the new offset in the adjusted stab section,
|
||
or -1 if the address refers to a stab which has been removed. */
|
||
|
||
bfd_vma
|
||
_bfd_stab_section_offset (output_bfd, psinfo, stabsec, psecinfo, offset)
|
||
bfd *output_bfd;
|
||
PTR *psinfo;
|
||
asection *stabsec;
|
||
PTR *psecinfo;
|
||
bfd_vma offset;
|
||
{
|
||
struct stab_section_info *secinfo;
|
||
|
||
secinfo = (struct stab_section_info *) *psecinfo;
|
||
|
||
if (secinfo == NULL)
|
||
return offset;
|
||
|
||
if (offset >= stabsec->_raw_size)
|
||
return offset - (stabsec->_cooked_size - stabsec->_raw_size);
|
||
|
||
if (secinfo->cumulative_skips)
|
||
{
|
||
bfd_vma i;
|
||
|
||
i = offset / STABSIZE;
|
||
|
||
if (secinfo->stridxs [i] == (bfd_size_type) -1)
|
||
return (bfd_vma) -1;
|
||
|
||
return offset - secinfo->cumulative_skips [i];
|
||
}
|
||
|
||
return offset;
|
||
}
|